• 한국환경보건학회지
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• 제36권5호
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• pp.351-359
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• 2010

The objectives of this study were to understand the characteristics of residents in industrial areas and factors affecting exposure to the Volatile Organic Compounds(VOCs : Benzene, Toluene, Xylene) as well as to assess exposure levels according to house-type, and whether residents were indoors or outdoors. This research was designed to assess the differences in exposure levels to indoor, outdoor and personal VOCs in a case group and a control group across all areas, as well as in each different area, from May to October 2007, in. 110 residents of the G, Y and H industrial areas of the Jun-nam province. The geometric mea-levels of airborne benzene for the case group 1.31part per billion(ppb) indoor, 1.29 ppb outdoor, and 1.32 ppb for personal exposure were significantly higher than for the control group 0.99, 0.87 and 0.57 ppb, respectively. The geometric mean level for toluene personal exposure across the G, Y and H areas was 5.70 ppb for the case group and 6.31 ppb for the control group. While the outdoor level was 4.27 ppb for the case group and 5.06 ppb for the control group, The indoor level for the case group was 4.78 ppb, similar to that of the control group 4.69 ppb. The geometric mean levels for airborne xylene across the G, Y and H areas were 0.16 ppb(outdoor), 0.12 ppb(personal exposure) and 0.10 ppb(indoor) for the case group, and for the control group were 0.17(personal exposure) and 0.09 ppb(indoor and outdoor). The indoor/outdoor(I/O) ratio for case group is 1.19, while that of the control group is 1.15, indicating that the indoor level was higher than the outdoor level. The interrelationship differences among the three different types of levels in the air in the G, Y and H areas are statistically significant, except for the difference between the indoor and outdoor figures for xylene. In terms of the different types of houses and energy type uesd, the geometric mean level for airborne benzene, toluene and xylene for houses were 1.61, 5.39 and 0.12 ppb, respectively. while the figures for flats were 0.67, 3.32 and 0.05 ppb, respectively. Outdoors, the levels of benzene and toluene in flats were 0.71 and 2.62 ppb, respectively. and 1.58 and 5.35 ppb in houses. For personal exposure, the house levels of benzene, toluene and xylene were all higher than for flats. Houses using oil for heating have significantly higher levels than flats, which use gas for heating.

• Journal of Oral Medicine and Pain
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• 제23권3호
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• pp.263-270
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• 1998

Considering various factors contributing oral malodor, the accurate prediction of prognosis is very important to both clinician and patients. The present study has been performed to invetigate the relationship between treatment effeicacy and pre-treatment volatile sulfur compounds (VSC) level. Ninety patients were divided into three groups, A(<150ppb), B(150< <200ppb), and C(>200ppb) groups, according to pre-treatment VSC level detected by Halimeter, and each group included 30 patients. Routine therapeutic measures for oral were provided to each patient which consisted of oral prophylaxis, tooth brushing and flossing instruction, tongue scraping by proper device, and gargling of 0.25% ZnCl2 Solution. The group with high pre-treatment VSC level (>150ppb) showed significant reduction of VSC level at 1 and 3 weeks after. However, the group with low pre-treatment VSC level (<150ppb) did not show any significant reduction during the experimental periods. Collectively, the results suggested that patients with high pre-treatment VSC level show better prognosis.

• Asian-Australasian Journal of Animal Sciences
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• 제10권1호
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• pp.1-7
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• 1997

This experiment was conducted with total 960 brown layers, consisted of 8 treatment to investigate the effects of dietary chromium as chromium picolinate on egg production, egg quality, nutrient utilizability, serum traits and mortality in brown layers. Layers were fed diets with two levels of dietary protein (14% and 16%) and supplemented with 0, 200, 400, 800 ppb/kg of chromium as chromium picolinate, respectively. The highest egg production, egg weight and egg mass were found in 800 ppb chromium picolinate supplementation group with high protein level (16%) (p < 0.05). Although there was no significant difference, layers receiving 400 ppb of chromium picolinate with high protein (16%) represented the lowest broken eggs. The utilization of energy, dry matter and crude protein of 400 ppb chromium picolinate group with low protein level (14%) were significantly higher than those of control or other chromium picolinate group (p < 0.05). 400 ppb chromium picolinate with low protein level (14%) showed the lowest serum glucose concentration. But serum glucose concentrations in all treatments showed no significant differences. Present date revealed that the lowest serum cholesterol concentration of layers was found at 400 ppb chromium picolinate group with high protein level (16%) (p < 0.05). Crude protein content in yolk was significantly higher in eggs of layers received 800 ppb chromium picolinate and the lowest in eggs from layers received 400 ppb chromium picolinate among chromium picolinate levels (p < 0.05). Mortality was remarkably decreased by chromium picolinate supplementation and the lowest mortality value was found in layres receiving 800 ppb chromium picolinate with high protein level.

• 대한수의학회지
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• 제61권1호
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• pp.7.1-7.7
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• 2021

The levels of aflatoxin (AFT) and ochratoxin (OCT) were assessed at different seasons in raw materials, different feed manufacture processing stages, and animal feeds in feed mills in Korea implementing the hazard analysis and critical control point (HACCP) system. Two hundred samples were collected in all four seasons from five feed mills implementing the HACCP system and examined for AFT and OCT contents. The AFT and OCT levels were analysed by using HPLC method to provide information on raw material and product stage. The AFT content of raw ingredients in the spring season was highest in corn gluten (3.84 ppb) and lowest in corn (1.82 ppb) The AFT content of corn was highest in the winter season (2.17 ppb). The content of OCT in wheat was highest in the winter season. The amounts of AFT and OCT at processing stages were higher than in the raw materials or feed. In particular, AFT content was higher in the transfer stage (3.88 ppb) than in the mixing (2.86 ppb) or filling stages (3.45 ppb) in the summer season. The means of AFT and OCT level in laying hen feed was 3.41 ppb and 1.14 ppb for broiler feed, respectively. The means of AFT and OCT level in and broiler feeds was 3.44 ppb and 1.17 ppb for broiler feed, respectively.

• 한국식품위생안전성학회지
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• 제16권3호
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• pp.200-205
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• 2001

시중 유통중인 유 및 유제품의 AFM$_1$의 오염수준을 파악하기 위해 분석한 결과 우유의 경우는 원유(0.083 ppb)에 비해 시유의 AFM$_1$농도(0.047 ppb)가 낮게 나타났으나 이는 살균의 효과라기보다 집유 과정에서의 희석 때문인 것으로 보이며, 탈지분유의 경우 AFM$_1$의 농도가 0.24 ppd로 높게 나타났으나 섭취시 희석되므로 우유와 큰 차이는 없을 것으로 생각되었다. 아이스크림제품의 경우 AFM$_1$오염농도는 0.020 pub로 나타났다. 이상의 결과는 미국 FDA의 허용기준치인 0.5 ppb보다 월등히 낮은 수치로 나타난 것이다. 국내 시판 우유 중 AFM$_1$오염수준을 평가하기 위해 본 연구의 결과와 기존의 국내 연구 결과를 토대로 Monte-Carlo 시뮬레이션을 시행하였다. 불확실성과 다양성을 고려하기 위해 fitting 절차를 거쳤으며, 시판 우유 중 AFM$_1$의 발생정도(prevalence)를 추정하기 위해 beta distribution을, 우유에서의 AFM$_1$오염농도(concentration)를 추정하기 위해 triangular distribution을 적용한 결과, 국내 시판 우유에서 AFM$_1$의 발생 가능한 오염수준(contamination level)은 최소(5% percentile) 0.0214, 평균(50% percentile) 0.0946 및 최대(95% percentile) 0.1888 ppb로 나타났다. 전체적으로 미국의 AFM$_1$허용기준치인 0.5 ppb보다는 상당히 낮은 수준이지만 시판우유의 80.4%근 유럽의 기준인 0.05ppb보다 높은 수준으로 예측되어 유럽의 허용기준치를 초과하는 것으로 나타났다.

• 한국식품위생안전성학회지
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• 제27권1호
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• pp.74-80
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• 2012

어류는 두뇌발달에 중요한 영양소이기도 하지만 신경독인 메틸수은을 함유하고 있는 것으로 알려져 있다. 메틸수은은 임산부가 임신 중에 태아의 두뇌에 치명적인 손상을 유발하는 것으로 알려져 있다. 따라서 연구자들은 생선소비와 임산부 제대혈 중의 메틸수은 함량을 확인하기 위하여 통영지역 임산부 159명을 대상으로 2010년 10월부터 2011년 3월 사이에 임산부의 생선소비와 제대혈의 수은농도의 관계를 조사하였다. 어류소비 관련자료는 설문조사를 통하여 수집하였고 통계처리는 one way ANOVA 를 이용하였다. 조사에 참여한 임산부의 평균나이는 30.1세이었고 임산부 제대혈의 수은 함량은 0.01-14.80 ppb 범위에 평균 $2.69{\pm}2.50ppb$이었다. 제대혈의 평균 수은함량은 WHO 기준인 5.0 ppb를 초과하지는 않았지만 159명 중 17명(10.7%)이 WHO 기준을 초과하였다. 연령별로는 30세 이상이 0.01-14.8 ppb 범위, 평균 $3.18{\pm}2.74ppb$로 29세 이하에서 0-8.00 ppb 범위, 평균 $2.04{\pm}2.00ppb$ 보다 1.6배 높았으며 유의적 차이가 있었다. 이 연구에서 생선섭취가 제대혈의 수은농도에 영향을 미치는 것으로 나타났다. 1주일에 3회 이상 섭취군이 평균 $4.15{\pm}4.02ppb$로 주 1-2회 섭취군의 $2.63{\pm}2.22ppb$, 먹지 않는 군의 $1.60{\pm}1.44ppb$ 보다 2.6배와 1.6배 각각 높게 나타났으며 적게 먹는 군과 먹지 않는 군과의 사이에는 유의적 차이가 없었고, 많이 섭취하는 군과는 유의적 차이 (p < 0.05)가 있었다. 이상의 결과에서 제대혈의 수은 농도는 생선섭취량과 관련이 있는 것으로 판단되며 가임기 여성이나 임산부에게 생선섭취를 제한하는 것이 제대혈의 수은 농도를 낮출 수 있고 향후 있을지도 모를 신생아의 신경발달 장애나 뇌 신경학적 손상을 줄일 수 있는 방법이라고 생각되었다.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2000년도 추계학술대회 논문집(Proceeding of the KOSME 2000 Autumn Annual Meeting)
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• pp.143-151
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• 2000

Dissolved silica is make some critical trouble at steam turbine. And, we must measure it to ppb level. We were looking for the best measuring method of the silica. Via this study, we could found it in the N-IR spectroscopy technology. This dissertation have been discuss about system structure, system fundamentals and performance test. At the test, we were study in the spectral interference of $NH_3$. We know that existing system had some problem. It is structural frailties of single beam type. Therefore we were study for double beam type structure. And we obtain a good result. In the result, it have been discuss that conduct a test of $NH_3$ effect.

• 한국대기환경학회지
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• 제15권2호
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• pp.159-173
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• 1999

Based on air quality monitoring data('89~'97) operated by the Department of Environment, we provide various fundamental statistics for ground ozone. The purpose of this paper are to review the national ambient ozone standard, to study spatial distribution of ozone. Since we, in Korea, calculate average ozone level, to examine the occurrences of ozone level 3 times a day (1~8, 9~16, 17~24 hours), the method does not seem to be scientifically sound comparing to a running average method adapted by the USEPA. When we counted the number of cases with 8-h average O3 level exceeding 60ppb(8-h average standard in Korea)and 80 ppb (that in the U.S.A) and also when we calculated 8-hour average ozone level based on th US method, some regions were classified as non-attainment areas. Especially in Seoul, results of spatial distribution analysis showed that high level ozone over 80 ppb was observed at Kuui-Dong and Pangi-Dong in the eastern part and at Ssangmun-Dong in the northeastern part. Also, occurrences of ozone episode defined as number of days then ozone level exceeding 80 ppb for 3 consecutive hours were extensively reviewed in this paper.

• 한국환경보건학회지
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• 제15권2호
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• pp.1-9
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• 1989

A pilot study was conducted in order to measure indoor and outdoor formaldehyde levels during August 3 - 22, 1988 in several underground spaces in Seoul. Formaldehyde concentrations were monitored during 1 week in selected sampling areas (subway station, underground shopping center, underpass, tunnel, underground parking lot) using passive formaldehyde monitors. In order to investigate a relationship between respiratory prevalence and levels of formaldehyde, each subject was asked to answer respiratory questions. The mean formaldehyde concentrations were 60.1 ppb in subway station, 122.2 ppb in underground shopping stores, 72.1 ppb in underpasses, 39.7 ppb in tunnel, and 75.9 ppb in underground parking lots, respectively. The mean indoor formaldehyde concentrations in underground environments varied from 28.6 ppb to 118.7 ppb. Generally, the mean formaldehyde concentrations in ticketing office in subway stations appeared higher than those level measured in platform. The mean formaldehyde concentrations of underground shopping center in Gangnam Terminal were higher than any other areas and it exceeded 100 ppb of the American Ambient Air Quality Standards of formaldehyde. Prevalence rates of respiratory symptoms of dwellers seemed to be related to higher indoor formaldehyde levels.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 춘계학술대회 논문집
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• pp.197-201
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• 2001

Measuring of the dissolved oxygen is widely used for the environmental control of natural waters, sewage waste treatment, medical and biochemical studies, soil husbandry, food and drug process control, and prevention of corrosion in boilers. Especially, a power plants need special management for preventing accidents from corrosion, therefore, it is essential to measure the concentration of dissolved oxygen in real-time. In this paper we present a method of measuring dissolved oxygen very accurately up to ppb units. This method, called polarographic method, is based on the measures of the electric current generated by the oxidation process in cathode and de-oxidation process in anode, assuming that the amount of the current is proportional to the density of dissolved oxygen.